Composition for impregnating wood



1Q6-1Sa05 Sept. 3, 1935. c. scHMnfuTZ D O O w G N I T A N G E R P M I RO F N O I T I S o P M O 0 Original Filed Sept. 28, 1934 I INVENTOR. CARLSCH/WTTUTZ ATTORNEYS.

\ a. s n {9 r a x "a af 1 i wi i 9 fires PATENT OFFICE COMlO SITION FORIMPREGNATIN G WOOD Carl Schmittutz, Bad Kissingen, Germany, as-

signor to Osmose Holzimpraegnierungs G. in. b. H., Leipzig, Germany, acorporation of Germany Original application September 28, 1934, SerialNo; 745,966. Divided and this application January 14, 1935, Serial No.1,590

solemn. (o1. 134-'l8.6)

This invention relates in general to the preserpenetrate the wood byosmosis, a water insoluble ,9. vation ofwood and in particular to animproved protective agent adapted, to penetrate the wood composition forimpregnating green wood which by capillary difiusion, water and asubstance is in a freshly cut and. moist condition to inadapted to formatacky paste with water. crease its resistance to decay and to attacksby. The invention accordingly comprises a cominsects and fungi. Thisapplication is a diviposition having the properties, the ingredientssion of my application Serial No. 745,966, filed and the proportion ofingredients all as set forth September 28,1934. hereinafter and thescope of the application of To facilitate the diffusion of theimpregnating which will be given in the claims. substance into the wood,it has hitherto been For a more complete understanding of the considerednecessary to cut the trees while the nature and objects of theinvention, reference 7 sap content is at the minimum, that is, duringshould be had to the following detailed descripthe winter. The cut treesare dried for a long tion taken in connection with the accompanyingperiod of time during which the wood frequently drawing, in which thefigure illustrates a view in becomes impregnated with spores of fungi,molds 3 section of a tree trunk after it has been treated 5 /and otherorganisms. The im tion is with the composition of the invention.

then carriednout with the ai gfifigm h Fonthapresemativeagenhthergisgmploygd a sureand. elevated emperature micESiiLfiJillgjhe watersoluble inorganic substance such, for exusewfia'ihpliga ted iarlwpensivea'pparatus iiiample, as sodium or gotassinmfifluggde, zinc cluditrgfi'iac'uum chambe'rsor immersion tanks chloride. Thmservative includesWat-e1: solug9 and means for heating the same. However, even bleinorganic fungicides such, for example, as with the expenditure of muchtime and expensive copper sulphate, potassium sulphide mercm'lcequipment, it has not been possible heretofore c osiIiEafT'Ti' desired,the preto extendth p a on throughout the e servative may comprise one ormore insecticides tire core of the trunk. such, for example, as asoluble arcsalt such 5 1 It is a general object of the invention toproas qg 1um qr potassium sodllgg g'. vide a composition for the preseygg f Wood potassium arseiia'te. The water soluble subv by a simple andeconomical process which ma e stam be eifiloyed either singly or inaduse of the natural phenomenon of osmosis to i t re The inorganicsubstance should be bring about the substantially complete impspreferably one with high solubility in water and 1 natlOl'LOf the woodwithout the use of vacuum, "high mobility, thatis, high osmotic pressureand. pressure or elevate ernpera e. 2: t f djflu5i0n I v,mailman-51118011 G 'ffi-ml'ention to Provide Further, the inventioncontemplates the use of a composition for impregnating the wood comtackypastes comprising t or more soluble prising a preservative, aningredient fixing the organic substances capflbluw 'g'ifi fo'rmpreservative so. as to prevent its escape when mmm gaiff i' .the wood issubjected to leaching by rain or mfififfiwfifl mfla e or an damp soil,and an agent which brings the ingre E tfiere may be ig-w'gt sgluble adients into intimate contact with the surface of orggdiigmgggmte such assodium. otassmm the wooddichrornate. Iii would appea'f'that th e llicfi40 It is specific object of the invention to mm is reduced within thewood, to a chrovide ggvel'composition for the preservation of mate saltwhich reacts with the fluoride or I Woodhamcterized by comprisingpreseltvative arsenate to form a diflicultly soluble product havadaptedto penetrate the wood by osmosis and mg the gener a1 structure of acryoflte compound a protective agent adapted to penetrate the wood bycapillary diffusion and to prevent the escape pmtecmve there gfi gi I rof the preservative from the wood, and a pasteorgamc sPbstance such gforming. substance adapted to bring the. preservam L E EEPMwLc$QQ-%%-tive and protective agents into intimate conmrmjve'cfive t 5 i igz g itact with the surface of the wood. substantlally insoluble 11 W e therob'ects of the invention will in part miscible therewith, and which hasalow 718430811237 oe obvious and will in part appear hereinafter, and ahigh toxicity toward fungi and insecfi 1 Generally speaking, the"composition of the The expression water insoluble organic $11 I :iinvention consists of a tacky paste comprising stance" shall includeorganic substances havin M i" a. water soluble preservative agentadapted to a relatively slight, solubility in water when compared to thewater soluble preservative agents 5 water swelling colloid such, forexample, as stargh, dextrine, disintegrated casein lue, gelmtfine, agara gf, wank. These ingredients are adapted'tcfgive a tacky paste withwater and may be used singly or in admixture with each 19 other.

In general, the preservative agent comprises from about 50% to 80%, theprotective agent from about 10% to 35% and the paste-forming glutinoussubstance from about 5% to 20% by 15 weight.

By way of illustration, but not by way of limiting the scope of theinvention, the following examples are given, the ingredients being inparts by weight:

Examples I II III IV V V} asodium fluoride... 900 900 Sodium arsenote.100 50 150 Sqdium dichrom 350 40 Dmltrophenol 170 170 50 35 70 Gumarabio 130 -l 30 Disintcgrated casein 150 l Starch 80 40 30 The severalingredients are ground and mixed I thoroughly with water in an amountsuificient to give a viscous paste of the required viscosity, andpreferably one having a high degree of tackiness.

If desired, the paste may comprise a wetting agent such, for example, asglycerine, to assist in bringing the preservative and the protectiveagent into more intimate contact with the wood. The hygroscopicity ofthe glycerine retards the drying out of the paste. There may be adde galso, if eesire rsutsneqes Marathi-2L eieeraee 61f to rejiler the samefi repfoof mothprooi, etc. -The comsasanfi of the inventiohisa'pplicable for use in various processes for the preservation of woodsuch for example as coating, dipping, inocculation, steeping in vatswith or without the application of pressure vacuum and elevatedtemperatures, and may be used with green. and partly seasoned wood orwith seasoned wood which has been previously moistened with water.

The composition is particularly adapted for use in the process claimedin my prior application Serial No. 745,966, in which the preservation ofgreen wood is carried out by stripping the bark from green treesimmediately after they have been cut down, coating the debarked surfacewith an aqueous paste comprising a water soluble prmervative andretarding the drying out of the coated wood until the preservative hasdifiused substantially into the wood.

There is illustrated in the figure the cross section or" a tree trunk iafter it has been treated with the composition of the invention. Thepreservative agent being a water soluble, inorganic salt, diii'uses byosmosis through the cell walls into the wood cells; it also diffusesthrough the capillaries and interstices between the cells. Ihepenetration of the water soluble preservative is rapid and to asubstantial depth as indicated by the area designated A. In time thesalt may difiuse completely throughout the heart wood 2 as well asthroughout the sap wood 3.

The protective agent, being an organic substance and insoluble in water,difiuses chiefly through the interstices between the cells. The depth ofpenetration of the protective agent is slight compared to that of thewater soluble preservative, the ratio oi the depths of penetration beingabout 1:4. The protective agent is con fined to the outermost layers asshown by the area designated B. This area B, impregnated by the waterinsoluble, organic substance, forms a 5 waterproof zone which preventsthe leaching out of the water soluble preservative when the treatedtimber is placed in damp soil or exposed to rain. In particular, thedinitrophenol appears to unite with the wood fibres and eilectivelyprevents the washing out of the water soluble ingredients of thecomposition.

The paste-forming colloidal substance serves the important purpose ofbringing the preservative and protective agents into intimate contactwith the surface of the wood and also retards the drying out of thewood. When the paste dries on the surface of the wood it forms a hornycoating designated C which prevents the paste from being washed ad orfalling oiT during the storing period. The paste fills the cracks H] inthe tree trunk so that, at these points, the inwardly diffusion is moreor less increased depending upon the depth of the crack.

Since the area of wood to be impregnated continuously decreases as thesalt diffuses inwardly the atmosphere and organisms. If the green treeis cut down when the sap is at the maximum. and the freshly cut treetreated with the composition of. the present invention, it frequentlyhappens that the osmotic difiusion of the water soluble preservativeproceeds to completion, including the heart wood, even after the outerlayers of the 3 tree have become air dry.

The composition of the present invention is applicable for thepreservation of various types of woods such, for example, as pine, fir,spruce, larch, beech, oak andash; womposition may beapplied to theentire-tneertrur iiior upon"finish. edneripari nnnished l mbe m cut fromtrees in a green condition. The composition is especially applicable forthe treatment of telegraph poles, fence poles, structural timbers andother woods used in the open. Trees intended for use as mine timber,cross ties and marine piles are preferably treated with the compositionscontaining fluoride and bichromate or another pair of inorganic saltscapable of forming an insoluble compound within the wood which isresistant to leaching when the wood is immersed in water or damp soil.

By the present invention there has been provided a novel composition forpreserving green wood having many new and unusual advantages. If thetree is treated before the wood has been attacked by insects and plantorganisms, the composition protects the wood from a later attack, andincreases the useful life of the wood. any cracks existing in thesurface of the wood are, filled with the paste in consequence of whichthe impregnation is deeper at these points and the protection at amaximum; The coating of aqueous paste and the action of the impregnatingsalt on the sap slows up the drying of the wood and retards thedevelopment of injurious cracks in the wood.

Further, the present paste is characterized by its simplicity ofcomposition and economy of ap-g; plication, despite which the depth ofpenetrationt is equal to or better than that obtained by the use ofaqueous solutions with vacuum, high pressure and elevated temperatures.

Since certain modifications in the composition "which embody theinvention may be made without departing from its scope. it is intendedthat all matter contained in the above description shall be interpretedas illustrative and not in a-limiting sense.

In the appended claims, the expression "green wood is intended todesignate both green wood containing live sapand wood which isrelatively freshly cut, although partially dried, and which has beenmoistened throughout with water.

I claim:

l. A composition for the preservation of wood, consisting of a viscoustacky paste comprising a water-soluble wood preservative adapted topenetrate the wood by osmosis, a water-insoluble protective agentadapted to penetrate the wood chiefly by capillary difiusion and retardtheleaching out of the preservative, water and a glutinous substanceadapted to form a water-swelling colloid and maintain the preservativeand protective agents in intimate, permanent and uniform contact withthe wood, said colloid adapted to give up water on drying to promote thedifiusion of the preservative into the wood.

2. A composition for the preservation of wood, consisting of a, viscoustacky paste comprising a water-soluble inorganic wood preservative,. a

water insoluble organic liquid protective agent adapted to penetrate thewood chiefly by capil- -'lary difiusion and retard the leaching out ofthe ,preservative, water and a glutinous substance adapted to form awater-swelling colloid and maintain the preservative and protectiveagents in intimate, permanent and uniform contact with the wood, saidcolloid adapted to give up water on drying to promote the diffusion ofthe preservative into the wood.

- 3. A composition for the preservation of wood, consisting of a viscoustacky paste comprising a water-soluble inorganic salt, a water-insolubleorganic liquid protective agent adapted to penetrate the wood chiefly bycapillary difiusion and retard the leaching out of the salt, water and aglutinous substance adapted to form a. waterswelling colloid andmaintain the preservative salt and the protective agent in intimate,permanent and uniform contact with the wood, said colloid adapted togive up water on drying to promote the diffusion of the salt into thewood.

4. A composition for the preservation of wood, consisting of a viscoustacky paste comprising a plurality of water-soluble inorganic saltsadapted to react within the wood to form a water-insoluble woodpreservative, a water-insoluble organic liquid protective agent adaptedto penetrate the wood chiefly by capillary difiusion and retard theleaching out of the preservative, water and a swelling colloid andmaintain the preservative salts and the protective agent in intimate,perglutinous substance adapted to form a water-' manent and uniformcontact with the wood, said colloid adapted to give up water on dryingto promote the diflusion of the salt into the wood.

5. A composition for the preservation of wood, consisting of a viscoustacky paste comprising from 50% to 80% of a water-soluble woodpreservative adapted to penetrate the wood by-osmosis, from 10% to 35%of a water-insoluble protective agent adapted to penerate the woodchiefly by capillary diffusion and retard the leaching out of thepreservative, from to 20% of a glutinous substance, and water in anamount suficient to form with said glutinous substance a water-swellingcolloid adapted to maintain the preservative and protective agents inintimate,

permanent and uniform contact with the wood and to give up water ondrying to promote the diffusion of the preservative into the wood.

6. -A composition for the preservation of wood, consisting of a viscoustacky paste comprising from 50% to 80% of a water-soluble inorganic woodpreservative, from 10% to 35% of a waterinsoluble organic liquidprotective agent adapted to penetrate the wood chiefly by capillarydif-' fusion and retard the leaching out of the preservative, from 5% to20% of a glutinous substance, and water in an amount sufficient to formwith said glutinous substance a water-swelling colloid adapted tomaintain the preservative and protective agents in intimate, permanentand uniform contact with the wood and to give up water on drying topromote the diffusion of the preservative into the wood.

7. A composition for the preservation of wood, consisting of a viscoustacky paste comprising from 50% to 80% of a water-soluble inorganic from50% to 80% of a plurality oi. water-soluble inorganic salts adapted toreact within the wood to form a water-insoluble wood preservative from10% to 35% of a water-insoluble organic liquid protective agent adaptedto penetrate. the wood chiefly by capillary difl'usion and retard theleaching out of the preservative, from 5% to 20% of a glutinoussubstance, and water in an amount suflicient to form with said glutinoussubstance a water-swelling colloid adapted to maintain the preservativeand protective agents in intimate, permanent and uniform contact withthe .wood

and to give up water on drying to promote the.

difiusion of the preservative into the wood.

CARL SCHMIIIUTZ.

consisting of a viscous tacky paste comprising

